Sensors used to measure Sandy's surge

Crews from U.S. Geological Survey offices in New York, Georgia and North Carolina fanned out across Long Island and the Empire State coastline Thursday to retrieve sensors that recorded how high storm surges rose and document how far inland they flowed.

In the days before the storm, crews from the USGS Water Science Center in Coram affixed 2-foot-long metal pipes to piers and poles at more than two dozen places on the North and South shores.

Inside each pipe was a sensor that would record wave heights every 30 seconds. The sensors also detect the exact moment of high tide and how long it takes for water to recede.

"You should see the whole shape, the whole peak of the tide," said USGS hydrologic technician Amy E. Simonson after she unscrewed the storm surge monitor from a post sticking out of Patchogue Bay.

Over the next 10 days, 22 USGS employees will revisit the shores of Long Island, Staten Island, lower Westchester and Manhattan to retrieve the sensors, said Ronald Busciolano, supervisory hydrologist at USGS in Coram.

Near the sensors they will also document debris fields on land to pinpoint how far the surge reached. And to give a better picture of the impact between the sensors, crews will try to document high tide markings at about 150 locations on Long Island and in New York City's boroughs.

Ten barometric pressure sensors were also deployed. USGS offices in other states did the same along their coasts.

The data will be used to calculate Sandy's impact, as well as help with future storm forecasts and modeling. Building designs and public safety plans could also be fine-tuned using the information collected.

"Any data we can get really helps better define how water moves through the different systems," Busciolano said.

A map detailing the information will be updated hourly on the USGS website. "People will be able to look and see how high water in an area hit," said Bryce McClenney, a USGS hydrologic technician from Raleigh, N.C.

The same equipment was deployed during last year's Tropical Storm Irene and helps give a sense of the differences between the storms.

"This was much worse," Busciolano said. "It was a much larger storm. It was a relentless funneling of water. It built up higher and higher."

To see the map, visit USGS.gov/hurricanes and click on Sandy Storm Tide Mapper.